Thanks for the update, I do run into a fatal error while reindexing

PHP Fatal error:  Call to undefined function _elgg_normalize_plural_options_array() in /mod/elgg_solr/lib/functions.php on line 1440

this function does not exist in 1.8. There is a function elgg_normalise_plural_options_array but just changing the function call is not sufficient. Some sql queries that follow are also not defined in 1.8 like _elgg_get_access_where_sql

I'm not getting that, this update was primarily done for a 1.8 site and it's running on there now, reindexed yesterday...

I deploy from git though, I suppose it's possible I screwed up the packaging or something.  Are you using this zip file or git?  If you're using this zip file see if deploying from git fixes it, and if so I'll redo the zip file.

I used the zip over here. I checked the github version just now and it has the same code https://github.com/arckinteractive/elgg_solr/blob/master/lib/functions.php#L1440

That code should only run in 1.9+
In 1.8 it uses the elgg_get_entity_guids_18() function instead. Look to find out why its using the wrong getter.

Found it. You are checking whether this is 1.9 or later with this function

function elgg_solr_is_elgg18() {
        if (is_callable('elgg_get_version')) {
                return false; // this is newer than 1.8
        }

        $is_elgg18 = (strpos(get_version(true), '1.8') === 0);

        return $is_elgg18;
}

While my setup is not 1.9 I do run a very nice plugin from Pawel Sroka (code analyzer).

And Pawel decided to introduce elgg_get_version() if it doesn't exist already. Ergo he was fooling your plugin that I was running 1.9

I am also struggling to find the best way to determine elgg version. Just checking if elgg_get_version() exists or is_callable is not sufficient I guess.

Ok, then I would say that's not a problem with this plugin...

I reversed the order of the call and that works for now.

True, but you might want to fix it anyway. It's not that hard. If you like I would make a PR for it, then you only have to accept it :-)

Sure

I would like to discriminate the search to give content with the user name first in results. That would also be a good idea for the community.

What should I manipulate for this ?

I'm not sure I understand what you mean by "give content with the user name first in results"

Sorry, I mean that the first results in search would be content I created.

You can pass parameters into the hooks - if you want to limit the results to your content you can create a filter query for your guid

$params['fq']['container_guid'] = 'container_guid:' . $user->guid;

If you want to just boost the results there's a way to do that, I can't remember how offhand and I don't know if there are params for it in this plugin.

Boost the results is the goal. I will play around with that. A person is probably most interested in himself, his friends and his groups (in that order). So I will boost those.